Neuroendocrine carcinoma (NEC) is a rare tumor, comprising < 1% of stomach cancers. A 55-year-old woman was referred to our hospital with biopsy-proven gastric cancer. A shallow ulcerative lesion was detected in the lesser curvature of the lower body. It was suspected to be early gastric cancer IIA + IIC type. Thus, endoscopic submucosal dissection was performed. She was subsequently diagnosed with NEC, which is aggressive and carries a poor prognosis. We conducted a radical resection and a laparoscopic-assisted distal gastrectomy. The tumor had infiltrated the subserosal layer and 6/42 lymph nodes were involved. The mitotic index was 16/10 high power fields and the Ki-67 labeling index was 26%-50%. The final diagnosis of NEC was made according to the World Health Organization 2010 criteria. She was suspected of having jumping metastasis to the proximal margin. The patient was treated with an oral anticancer drug (5-flurouracil based drug) for 2 years. The patient has been followed up for 3 years without recurrence.
Keywords: Gastrectomy; Ki-67; Mitosis; Neuroendocrine carcinoma; Prognosis.